Electric switch with time control mechanism



1942- w. F. EDWARDS ET AL 2,273,751

ELECTRIC SWITCH WITH TIME CONTROL MECHANISM Filed Jan. '7, 1939 2Sheets-Sheet l Illll INVENTOR WILLIAM F. EDWARDS JOHANNES R. CARLSON BYTHEIR ATTORNEYS Feb. 17, 1942.

w. F. EDWARDS ET AL ELECTRIC SWITCH WITH TIME CONTROL MECHANISM FiledJan. 7, 1959 2 Sheets-Sheet 2 WILLIAM F. EDWARDS JOHANNES R. CARLSON BYTHEIR ATTORNEYS time interval.

Patented Feb. 17, 1942 'UNITED STATES PATENT OFFICE ELECTRIC SWITCH WITHTIME CONTROL MECHANISM William F. Edwards, West Hartford, and JohannesR. Carlson, Hartford, Conn., assignors to The Arrow-Hart & HegemanElectric Company, Hartford, Conn., a corporation of ConnecticutApplication January 7, 1939, Serial No. 249,814

8 Claims.

This invention relates to electric switches for controlling pluralcircuit arrangements such as for example in electric ranges and thelike. More particularly the invention relates to a switch for multiplecircuit control which is provided with means to automatically change thecircuit connections after the passage of a predetermined It is an objectof our invention to provide a multiposition rotary electric switch forcontrolling multiple electric circuits which will be capable of changingthe circuit connections after a selected time interval, and which may bemanually moved at any time to any one of a plurality of circuit-makingpositions. 7

Another object of our invention is to provide a cam-operated type ofrotary switch for use with electric range circuits and the like whichmay be operated by a time control mechanism after a selected timeinterval and which permits quick separation of the electric contacts atthe instantof circuit interruption. I

Another object of our invention is to provide a switch of the above typewhich may have the time control mechanism assembled therein as aseparate unit.

Other objects and advantages of our invention will become apparent asthe invention is described in connection with the accompanying drawings.

In the drawings:

Figure 1 is a plan view of an electric switch embodying the principlesof our invention;

Figure 2 is an elevation view partly in vertical section of the switchin Figure 1;

Figure 3 is a fragmentary detail view of the connection between theswitch spindle and the time control mechanism of the invention;

Figure 4 is a view looking into the bottom 01 the switch in Figure lwith the time control mechanism removed;

Figure 5 is a plan view of the time control,

mechanism as removed from the switch ure 4;

Figure 6 is a view similar to Figure 4, but with the parts in theposition they occupy when the switch is set for a -minute time interval;

in Fig-' Figure 7 is a view similar to Figure 5, but withthe timemechanism Figure 6;

Figure 8 is'a fragmentary detail view showing in plan one of the lineterminals and its asso ciated switch contacts and their cooperation withthe operating cam switch spindle.

in position corresponding to Figure 9 illustrates in plan another of theline terminals and its associated movable contact.

Referring to the drawings, the switch comprises a two-part casing ofmolded insulatingmaterial in which the switch parts are housedPreferably, the casing will have plane side and top walls and will havethe operating parts mounted upon the base 2 over which the hollow,cup-like" cover I fits to enclose and protect the switch parts.Conveniently, the base 2 may be hollowed out from the bottom to receivea clockwork mechanism 10 as hereinafter described.

The switch is operated by a dial handle 3 afiixed upon a spindle l whichextends through the cover I and has 'mounted thereon four cams, such asand 25. These cams are loosely mounted upon but are required to movewith the switch spindle by mounting means of the type described in thecopending application of Louis A. Yeske, Serial No. 140,705, entitledRotary switch, now Patent 2,182,715, dated December 5, 1939. But thepresent construction differs from the Yeske invention in the respectthat the cams are permitted lost motion relative to the spindle.Briefly, the movement of the cams with the spindle is compelled by theengagement therewith of a member 6 which is keyed to and moves as a unitwith the spindle 4 and has arms 6a extending parallel to the spindlethrough apertures, for example 35a, in the cams. Preferably, theapertures are larger than the cross section of the member Ba, so thatthe cams are permitted a small amount of movement rela tive to thespindle and-the operating member 6 for a purpose to be hereinafter morefully described. The cams may be spaced by washers, for example 36, 38,afiixed to the spindle. If desired the cams and their securing memberand spacing washers may be secured in assembled position by peaning overthe ends of the securing member under the bottom cam, or they may besecured by a separate anchor disc keyed to the spindle below the bottomcam as in the Yeske invention.

The switch is provided with three line terminals I0, 20, and 30 whichhave attached to upstanding arms thereof similar spring contact fingerseach of which has on its free end a contact button, that is, springfingers 32 and 33 are mounted upon arms bent up from the sides of theterminal 30 and have contact buttons 3| and 34 mounted on their freeends, respectively. In like manner, the spring finger I l is mountedupon an upstanding arm (not visible) of the terminal I0 and has acontact button l2 while spring like manner, the movable contact buttonll engages and disengages the stationary contact 42 and the movablecontact button 2| engages and disengages the fixed contact 5| as theirrespective cams (not visible) are rotated by the switch spindle. In viewof the complete disclosure of this type of cam-and-spring switchmechanism in the previously mentioned application of Louis A. Yeske, afurther illustrationand descriptionof this mechanism will not benecessary. It will be understood by those skilled in the art that bymaking appropriate wire connections between the line and load terminalsand a suitable resistance unit, various degrees-of heat, such as high,medium and low heats, may be obtained as the switch is manipulated. Itwill be understood, however, that the switch is not limited to use witha resistance unit.

For the purpose of controlling the movement of the switch spindle andmovable contacts a conventional time control mechanism or clockworkdesignated generally by the numeral may be secured in the bottom of theswitch casing. The clockwork of this mechanism may be of any suitabletype or construction, it only being necessary to have the clockmechanism proportioned so as to rotate its main arbor 12 the requiredamount within a specified period so as to impart a sufficient rotationto the switch spindle 4 to cause operation of the switch contacts at theend of the predetermined interval as hereinafter described.

In order that the motion of the clock mechanism may be imparted to theswitch spindle 4 and in order that the manual movement of the switchspindle may be imparted to the clock mechanism for the purpose ofwinding the same, a disc 13 with a notch 14 therein may be mounted uponan end of the clock arbor 12 which extends toward the switch mechanismand is coaxial with the switch spindle. For engaging with the disc 13 adisc 8|] may be rigidly attached to the end of the switch spindleadjacent the disc 13 and may have a projection 8| extending from theface of the disc parallel to the spindle 4 in position to engage in thenotch I4, so that the switch spindle 4 and the clock arbor 12 will moveas a unit. Preferably, the clock mechanism will be of the type in whichrotation of the arbor in one direction will wind the clock spring andset the mechanism for a predetermined period, and which will permit thereversal of the arbor to unwind the spring and nullify or vary theprevious setting, when it is desired to do so manually.

To this end a spring clutch disc 90 may be fixed for movement with thclock arbor and may press upon a driving gear 92 of the clock mechanismin conventional fashion so as to move with the gear as the clockmechanism unwinds normally. When the handle is reversed, manually, tonullify a previous clock setting, the disc 90 will slip on the face ofthe gear 92.

In order that the switch contacts may be held in their variouspositions, a radial projection 82 is provided upon the disc 80, whichprojection engages with an indexing spring 84 which may casing extendinginto the countersunk recess 89. When the switch is in medium positionthe projection 82 will have moved about 45 counter clockwise from theFigure 4 position, to engage in the indentation 86; and when the switchis in the low position the projection 82 will have moved about 45 morein counter-clockwise direction. In that position the clockwork which isunder a slight initial tension will hold the projection 82 as againstthe shoulder 81. Movement of the switch about 135 counter-clockwise fromFigure 4 will place it in high heat position. While in high position itwill be at all times under the effort of the clock mechanism and willremain in the high heat position only so long as the time interval atwhich the clock mechanism has been set has not elapsed.

As previously described, the operating member 6 loosely engages theoperating cams by reason of the large size apertures 3511, therebyproviding lost motion between the operating cams and the member 6. Thislost motion permits the pressure of the contact springs, as the camengaging port-ions (320 for example) start to move down into thedepressed parts 35d of the cam, to move the cams relatively to theiroperator 6.

Thus. the contact springs may snap the contact buttons which they carryaway from the corresponding stationary contact buttons as the switch ismoved automatically into low heat position by the clock mechanism. Ifthis lost motion means were not provided the separation of the contactsautomatically would be very slow and would be accompanied byconsiderable arcmg.

In operation the switch may be moved manually into any position byrotation of the dial handle 3. It will remain in either off, medium orlow positions permanently, that is, until manually moved into anotherposition. The indexing spring prevents the clock mechanism from movingthe switch from any of those positions. But, on movement into high heatposition, the handle is turned until the pointer (Figure 1) indicatesthe time interval that it is desired to have the switch remain in highheat position. When such interval elapses the operating cams will moveinto low position. Just as they do so, the lost motion between them andtheir operator 6 will allow the contacts and cams to move independentlyof the operator 6 so as to permit the contacts to snap into their lowposition.

If it is desired to change the setting of the switch after it has oncebeen set for a certain time interval this may be done by manipulatingthe handle, which will either wind the clock further or unwind it,depending on the direction in which the handle is turned.

From the foregoing, it will be seen that we have provided a novelconstruction of switch mechanism which is particularly adapted for usein rotary heater switches for the purpose of controlling automaticallythe movement of the switch from high heat or other position into a lowheat'or other position when the time interval for which the switch hasbeen set has elapsed. Also our invention may be assembled in a simpleand expeditious manner by incorporating the clock mechanism in thecombination after the switch itself has been fully assembled. By reasonof our construction, repair, replacement or cleaning of the clockmechanism may be easily and quickly accomplished, or switch parts may bereplaced without disassembling the parts which make up the clockmechanism. We have also provided means for permitting the contacts tosnap into low heat position as the end of the interval of high heat isreached.

Obviously the terms high, medium and low heat positions are simplyrelative and are used for convenience in designating different positionsof a switch which is adaptable generally to multiple circuit control.

Th inventionmay be adapted for use in moving the contacts either into orout of any desired switch position. Such adaptations and manymodifications within the erating said shaft, cam means operated by said.shaft for moving said contacts into one switch scope of our inventionwill occur to those skilled in the art. Therefore, we do not limit theinvention to the specific embodiment described.

1. In a manually and automatically operable switch, a plurality ofseparable switch contacts connectible in at least two differentclosed-circuit positions and an open-circuit position, manuallyrotatable means movable in both clockwise and counterclockwisedirections, rotary cam means for causing engagement and disengagement ofsaid contacts at will into all of said positions, and a lost-motionconnection between said manual means and said cam means, and meanssettable by rotation of said manual means for moving said contacts atthe end of a "selected time interval from one 'of said positions toanother position with a snap action.

2. In a manually and automatically operable switch, a plurality ofseparable switch contacts connectible in at least two, differentclosed-circuit positions and an open-circuit position, manuallycontrollable cam-operatingmeans including a lost-motion connection forcausing engagement and disengagement of said contacts at will into allof said positions, and means settable to move said contacts at the endof a selected time interval from one of said positions to anotherposition with a snap action, a separable connection between saidsettable means and said camoperating means whereby said settable meansposition from another, a lost-motion connection between said cam meansand said shaft whereby contact operation occurs with a snap-action atthe end of the selected time interval, and manual means for operatingsaid shaft in both clockwise and counterclockwise directions to movesaid contacts into at least two closed-circuit positions and anopen-circuit position at any time.

6. In a rotary switch, an operating shaft, a plurality of separableswitch contacts connectible in at least two different closed-circuitpositions and an open circuit position, retarded-action means settablefor selected time intervals for operating said shaft, cam means operatedby said shaft for moving said contacts into one switch position fromanother, a lost-motion connection between said cam means and said shaftwhereby contact operation occurs with a snap-action at the end of theselected time interval, and manual means for operating said shaft inboth clockwise and counterclockwise directions to move said contactsinto at least two closed-circuit positions and an open-circuit positionat any time, and to set said retarded means.

7. In a rotary switch, an operating shaft, a plurality of separableswitch contacts connectible in at least two different closed-circuitpositions and I an open circuit position, retarded-action means settablefor selected time intervals for operating said shaft, cam means operatedby said shaft for moving said contacts into one switch .ing constructedand arranged to be deenergized when said manual means is actuated in onedirection to move said contacts from the position in said operatingmeans and said contacts, and means settable to move said contacts at theend of a selected time interval from one of said positions to anotherposition with a snap action, a separable connection between saidmanually operable means and said settable means whereby said settablemeans may be assembled and removed asa unit from the switch.

4. In a manually and automatically operable switch, a plurality ofseparable switch contacts connectible in at least two differentclosed-circuit positions and an open-circuit position, manuallyoperatable means to cause engagement and disengagement of said contactsat will into all of said positions, and means settable to operate whichthe retarded'means is operating upon them.

8. In a rotary switch, a plurality of separable switch contactsconnectible in at least two different closed-circuit positions and anopen ciricuit position, an operating shaft, manually controllable meansfor operating said shaft, re-

- tarded-action means in which energy is.st0red said contacts at the endof a selected time in terval from one of said positions to another, aseparable connection between said manually operable means and saidsettablemeans whereby said settable means may be assembled and removedas a unit from the switch. r

by rotation of said shaft, said retarded-action means being settable forselected time intervals for operating said shaft, cam means operated bysaid shaft for controlling contact separation and engagement, and alost-motion connection between said cam means and said shaft wherebycontact operation .occurs with a snap-action at the end of the selectedtime interval, and a separable connection between said retarding meansand said shaft permitting assembly and removal of said retarding meansas a unit inand from the switch. 1

WILLIAM F. EDWARDS. JOHANNES R. 'CARLSON.

